The average score of a batsman after his 50th innings was 46·4. After 60th innings, his average score increases by 2·6. What was his average score in the last ten innings?
- (a) 122
- (b) 91
- (c) 62 ✓ UPSC's answer
- (d) 49
Why the answer is (c)
• Calculate the total runs scored in the first 50 innings: 50 × 46.4 = 2320.
• Determine the new average after 60 innings: 46.4 + 2.6 = 49.0.
• Calculate the total runs scored in the first 60 innings: 60 × 49.0 = 2940.
• Find the runs scored in the last 10 innings by subtracting the first 50 innings' total from the 60 innings' total: 2940 - 2320 = 620.
• Calculate the average score for the last 10 innings: 620 / 10 = 62.
• Therefore, the correct option is (c).
Why the other options are wrong
- (a) 122
- 122 is incorrect because it significantly overestimates the runs required to raise the average by only 2.6 runs over 10 innings.
- (b) 91
- 91 is incorrect because it does not match the calculated total of 620 runs for the last 10 innings.
- (d) 49
- 49 is incorrect because it represents the new overall average after 60 innings, not the average of the last 10 innings.
Asked in the CSAT Paper II of the UPSC Civil Services Preliminary Examination 2020, held on 4 October 2020. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.